Part of my chair broke a couple months ago (the piston part) and unfortunately AKRacing went out of business so I can't fix the chair, therefore I am selling off the useable parts from the chair I have since I can't fix it so look for my other listings. My chair was max series, but I believe some of these parts are interchangeable with other AKRacing Series, but check your part numbers to make sure. This part is the under carriage of the chair that the wheels insert onto. The wheels are not included this is just the under carriage. Any questions feel free to ask. This part measures 26" L x 26" W x 13" H.